Magnetic and structural properties of SmCo6.75-xFexZr0.25 compounds

Bulk alloys of SmCo6.75-xFexZr0.25, where x=0, 0.27, 0.41, and 0.54 were pr epared by are-melting. The alloys were characterized by X-ray diffraction, vibrating sample magnetometer, and SQUID magnetometer. X-ray diffraction sh ows that these compounds form the hexagonal TbCu7-type structure for x<0.67 and for large values of x (x greater than or equal to 0.67) the hexagonal TbCu7-type structure cannot be formed. The lattice parameters (a and c) are dependent on the iron concentration. The unit cell volume is found to incr ease with x which is due to the larger atomic volume of Fe. X-ray diffracti on and magnetization measurements on magnetically aligned samples show that all the samples studied have uniaxial anisotropy. The saturation magnetiza tion increases with x at both room temperature and 5 K. The Curie temperatu re for these compounds is about 770 degrees C for all values of x under inv estigation. (C) 2000 Elsevier Science S.A. All rights reserved.